No tenant has yet been identified for the 250,000-square-foot building, but construction could begin as early as mid-2015, City Center spokesman Jeff Vaughan said. The building could be as many as seven floors tall.

Planned for Walnut Street between Seventh and Eighth streets, the building could serve up to 1,000 workers and will include a 1,078-space parking deck, which will include some underground parking.

The final size will depend on the tenants secured for the building, and Reilly could later modify the plans to reduce the building's size if necessary.

Five City Center is designated for the spot where Reilly planned his first building three years ago, Vaughan said, but he has since acquired other properties and it took a back seat to other developments.

All those projects fall within the city's 130-acre Neighborhood Improvement Zone tax district, which diverts new state and local nonproperty taxes into development at portions of the city's waterfront and Downtown neighborhoods.